冬季猪粪固体堆放过程中NH3、N2O和NO排放特征研究

针对农村猪粪典型处理方式中的固体堆放管理,研究猪粪在冬季(2012年11月~2013年2月)固体堆放过程中NH3、N2O和NO排放特征.实验共设两个处理——无覆盖(non-covered,NC)和水稻秸秆覆盖(covered,C),堆放时间为73 d,期间进行了3次翻堆操作.实验观测了3种含氮气体(NH3、N2O和NO)的排放通量和堆体剖面N2O浓度变化.结果表明,猪粪固体堆放过程中NH3、N2O和NO排放累积量(以N计)分别占初始TN的比例为2.1%~2.6%、0.02%和~0.000 25%.两个处理的含氮气体排放通量变化趋势基本一致,且有覆盖堆体的含氮气体的排放量略低于无覆盖堆体.在堆放初期,NH3排放量最先出现峰值,之后N2O和NO排放开始增加.NH3和NO在固体堆放的中前期呈现互为消长的变化趋势;到堆放后期,N2O开始出现比前期高出两倍的排放高峰,而NH3和NO出现小幅增长.翻堆前后,NH3的排放无明显变化,而N2O排放在翻堆后均出现降低的变化,NO排放却出现升高的变化.

Emissions of NH3, N2O, and NO from Swine Manure Solid Storage in Winter

Swine manure solid storage is a typical management in rural area of China. In order to investigate the characteristics of NH₃, N₂O and NO emissions during manure storage in winter (Nov., 2012 to Feb., 2013), two treatments were conducted: non-covered (NC) and covered (C) with straws, and each treatment had three times of pile-turning during the 73 days storage. The emission fluxes of three nitrogen gases (NH₃, N₂O and NO) were measured and the profile-N₂O concentrations inside the swine pile profile and in the soil under the pile were also measured. The results indicated that 2.1%-2.6%, 0.02% and ~0.00025% of total nitrogen were lost in the form of NH₃, N₂O and NO respectively during the whole swine manure solid storage. The nitrogen gases in the two treatments had the same variation characteristics, but all the nitrogen gases were reduced in the covered treatment. In the early storage stage, NH₃ emission peak occurred first and then the emissions of N₂O and NO started increasing. In the middle storage stage, the emissions of NH₃ and NO showed mutual growth and decline trend. In the late storage stage, N₂O emission peak was twice higher than that in the early stage, while NH₃ and NO emissions showed a slight increase. Before and after pile-turning operation, NH₃ emission had little change, but N₂O emission was decreasing and NO emission was rising after pile-turning.